Highly conductive transparent laminated glass article

ABSTRACT

A highly conductive transparent laminated glass article includes two glass plates and an adhesive film. The adhesive film has a material of Poly(Vinyl Butyral) (PVB) resin and is located between the two glass plates. At least one of the two glass plates is a highly conductive transparent glass-based circuit board with a glass substrate. A surface of the glass substrate is not contact with the adhesive film. A conductive paste, printed on the surface of the glass substrate, is baked, heated, and cooled to form a conductive circuit fused with the surface of the glass substrate. The surface of the glass substrate and an upper surface of the conductive circuit are at the same level. The highly conductive transparent laminated glass article has the characteristics of high conductivity and high light transmittance. The highly conductive transparent laminated glass article is suitable for fabrication, manufacture, and use of industrial and smart-home devices.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the National Stage of International Application No.PCT/CN2017/072576 filed on Jan. 25, 2017, which claims benefits ofChinese Application No. 201610075787.7 filed on Feb. 3, 2016, thedisclosure of which is incorporated by reference.

TECHNICAL FIELD

The present invention relates to a highly conductive transparentlaminated glass article, and more particularly to a highly conductivetransparent laminated glass article, which belongs to the field ofmanufacturing an electronic device.

BACKGROUND

A laminated glass article of the prior art is commonly used as a safetyglass article or a sound-insulated glass article in building andautomotive fields. The laminated glass article of the prior art isessentially composed of two glass plates and an adhesive film. Ingeneral, the adhesive film has a material of Poly(Vinyl Butyral) (PVB)resin and is located between the two glass plates. With the advance ofscience and technology, a conductive circuit has been embedded in thelaminated glass article for wildly used in industrial and smart homedevices.

However, a glass-based circuit board in the laminated glass article ofthe prior art is commonly manufactured by a coating and etching processor a low-temperature silver paste process. The coating and etchingprocess is to coat a conductive paste on a glass substrate and then toetch the conductive paste to form a conductive circuit. That is, theconductive circuit is bonded to the glass plate through an adhesive.Because glass molecules cannot chemically react with any element exceptfluorine, the coating and etching process is basically a sprayingtechnique, which is a bonding process of organic materials mixing withconductive metal particles. The adhesive reduces the purity of theconductive paste so the conductive capability of the conductive circuitis very poor, wherein the electrical impedance of the best material isonly 1×10⁻⁴ Ω. It is difficult to weld electronic components, and it isalso difficult to implement functional circuits. The low-temperaturesilver paste process is to print a silver paste on a surface of a glasssubstrate through a screen printing technique, and then to bake andcuring at a temperature of less than 200° C. to form a conductivecircuit. The low-temperature silver paste process cannot achieve highconductive capability because the silver paste contains a large amountof organic bonding materials. The electrical impedance of the conductivecircuit can only reach 3×10⁻⁵ Ω. It is still difficult to weldelectronic components, and it has poor adhesion. Due to the limitationof the two processes, the glass substrate and the conductive circuit arenot tightly bonded, and a surface of the conductive circuit is higherthan the surface of the glass substrate. Because a surface of theglass-based circuit board is not smooth, the conductive circuit iseasily damaged and peeled off, resulting in poor conductive capability.

SUMMARY

For solving the above problems of the prior art, the present inventionis to provide a highly conductive transparent laminated glass article. Aconductive circuit is tightly fused with a glass substrate. It is afusional relation between the conductive circuit and the glasssubstrate. A surface of the glass substrate and an upper surface of theconductive circuit are at the same level. Because a surface of thehighly conductive transparent glass-based circuit board is smooth, theconductive circuit is not easily damaged. The highly conductivetransparent glass-based circuit board has the characteristics of highconductivity and high transmittance. The highly conductive transparentlaminated glass article is suitable for wildly used in industrial andsmart home devices.

For solving the above problems of the prior art, the present inventionis to provide a highly conductive transparent laminated glass article,which includes two glass plates and an adhesive film. The adhesive filmhas a material of Poly(Vinyl Butyral) (PVB) resin and is located betweenthe two glass plates. At least one of the two glass plates is a highlyconductive transparent glass-based circuit board with a glass substrate.A surface of the glass substrate is not contact with the adhesive film.A conductive paste, printed on the surface of the glass substrate, isbaked, heated, and cooled to form a conductive circuit fused with thesurface of the glass substrate. The conductive circuit is madeessentially of a graphene layer or a conductive layer. The conductivelayer has a graphene upper portion and a metal lower portion fused withthe glass substrate, and a surface of the graphene upper portion isfused with a surface of the metal lower portion. The glass substrate isa glass-tempered substrate. A surface of the conductive circuit, excepta region reserved for a solder pad used for welding a component, iscovered with a printed-circuit-board (PCB) organic solder-resistantlayer.

The surface of the glass substrate and an upper surface of theconductive circuit are at the same level.

The conductive paste includes conductive powder, low temperature glasspowder, ethyl cellulose, terpineol, and dibutyl maleate. A mass ratio ofconductive powder:low temperature glass powder:ethylcellulose:terpineol:dibutyl maleate is 65 to 75:3:5 to 10:10 to 20:1 to3. The conductive powder is graphene powder or a mixture of metal powderand graphene powder. When the conductive powder is the mixture of metalpowder and graphene powder, the graphene powder accounts for 2% to 5% bymass of the conductive paste.

A surface of the glass-tempered substrate faces air, and the conductivepaste, printed on the surface of the glass-tempered substrate, is bakedat a temperature between 120 and 150° C. for 100 to 200 seconds, placedat a temperature between 550 and 600° C. for 300 to 360 seconds, thenplaced at a temperature between 710 and 730° C. ° C. for 120 to 220seconds, and finally cooled to form the conductive circuit fused withthe surface of the glass-tempered substrate.

The thickness of each of the two glass plates is 5 mm to 8 mm.

The thickness of the adhesive film is 1 mm to 2 mm.

The thickness of each of the two glass plates is 6 mm, and the thicknessof the adhesive film is 1.14 mm.

The highly conductive transparent laminated glass article of the presentinvention has the advantages described as follows:

(1) The conductive circuit is tightly fused with the glass substrate. Itis a fusional relation between the conductive circuit and the glasssubstrate. The highly conductive transparent glass-based circuit boardhas the characteristic of superconductivity, wherein the electricalimpedance of the conductive circuit of the highly conductive transparentglass-based circuit board is lower than 5×10⁻⁸ Ω.

(2) The conductive circuit is fused with the glass substrate without anybonding medium so the conductive circuit has the characteristic of goodthermal conductivity in high power applications. The conductive circuitis tightly fused with surface molecules of the glass substrate, whereina surface-mounted-device (SMD) can be bonded on the conductive circuitand the surface-mounted-device (SMD) is not easily peeled off.

(3) The graphene powder accounts for 2% to 5% by mass of the conductivepaste. Although the content of the graphene in the conductive paste isvery little, the arrangement of molecules of the graphene are extremelydense, molecules of the graphene are light to enable to float on thesurface of metal molecules, wear resistance of the graphene is higherthan wear resistance of metal, and the graphene has high conductivity.Thus, the conductive circuit has still high conductivity. The grapheneis almost transparent so that the highly conductive transparentglass-based circuit board has high light transmittance of more than 90%.

(4) The surface of the glass substrate and the upper surface of theconductive circuit are at the same level. Because a surface of thehighly conductive transparent glass-based circuit board is smooth, theconductive circuit is not easily damaged.

(5) The conductive circuit is coated with the printed-circuit-board(PCB) organic solder-resistant layer, wherein the surface of theconductive circuit, except the region reserved for the solder pad usedfor welding the component, is covered with the printed-circuit-board(PCB) organic solder-resistant layer. This coated process of the presentinvention is named for the second coated process. The second coatedprocess is used for protecting the conductive circuit and preventingoxidation of the surface of the conductive circuit so as to maintain theability of superconductivity.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic view showing the structure of a highly conductivetransparent laminated glass article according to the present invention.

FIG. 2 is a schematic view showing the structure of a highly conductivetransparent glass-based circuit board according to the presentinvention.

FIG. 3 is a cross sectional view taken along line A-A of FIG. 2.

FIG. 4 is a cross sectional view showing the structure of a highlyconductive transparent glass-based circuit board covered with aprinted-circuit-board (PCB) organic solder-resistant layer according tothe present invention.

In the figures: numeral 1 represents highly conductive transparentglass-based circuit board; numeral 1-1 represents glass substrate;numeral 1-2 represents conductive circuit; numeral 1-3 represents solderpad; numeral 1-4 represents PCB organic solder-resistant layer; numeral1-5 represents graphene upper portion; numeral 1-6 represents metallower portion; numeral 2 represents PVB adhesive film; and numeral 3represents glass plates.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The present invention will be further described below in conjunctionwith accompanying drawings and exemplary embodiments.

Please refer to FIGS. 1 to 3. The present invention provides a highlyconductive transparent laminated glass article. The highly conductivetransparent laminated glass article includes two glass plates 3 and anadhesive film 2. The adhesive film 2 has a material of Poly (VinylButyral) (PVB) resin and is located between the two glass plates 3. Atleast one of the two glass plates 3 is a highly conductive transparentglass-based circuit board 1 with a glass substrate 1-1. A surface of theglass substrate 1-1 is not contact with the adhesive film 2. Aconductive paste, printed on the surface of the glass substrate 1-1, isbaked, heated, and cooled to form a conductive circuit 1-2 fused withthe surface of the glass substrate 1-1. The conductive circuit 1-2 is amade essentially of a graphene layer or a conductive layer. Theconductive layer has a graphene upper portion 1-5 and a metal lowerportion 1-6 fused with the glass substrate 1-1, and a surface of thegraphene upper portion 1-5 is fused with a surface of the metal lowerportion 1-6. The surface of the glass substrate 1-1 and an upper surfaceof the conductive circuit 1-2 are at the same level.

The conductive paste includes conductive powder, low temperature glasspowder, ethyl cellulose, terpineol, and dibutyl maleate. A mass ratio ofconductive powder:low temperature glass powder:ethylcellulose:terpineol:dibutyl maleate is 65 to 75:3:5 to 10:10 to 20:1 to3. The conductive powder is graphene powder or a mixture of metal powderand graphene powder. When the conductive powder is the mixture of metalpowder and graphene powder, the graphene powder accounts for 2% to 5% bymass of the conductive paste.

The glass substrate 1-1 is a glass-tempered substrate. A surface of theglass-tempered substrate faces air, and the conductive paste, printed onthe surface of the glass-tempered substrate, is baked at a temperaturebetween 120 and 150° C. for 100 to 200 seconds, placed at a temperaturebetween 550 and 600° C. for 300 to 360 seconds, then placed at atemperature between 710 and 730° C. for 120 to 220 seconds, and finallycooled to form the conductive circuit 1-2 fused with the surface of theglass-tempered substrate.

The glass substrate 1-1 is the glass-tempered substrate.

The thickness of each of the two glass plates 3 is 5 mm to 8 mm.

The thickness of the adhesive film 2 is 1 mm to 2 mm.

The thickness of each of the two glass plates 3 is 6 mm, and thethickness of the adhesive film 2 is 1.14 mm.

Please refer to FIG. 4. A surface of the conductive circuit 1-2, excepta region reserved for a solder pad 1-3 used for welding a component, iscovered with a printed-circuit-board (PCB) organic solder-resistantlayer 1-4.

The manufacturing process of the highly conductive transparentglass-based circuit board 1 is described as follows:

Step (1): To print the conductive paste on the surface of the glasssubstrate 1-1, wherein the surface of the glass substrate 1-1 faces air.The conductive paste includes conductive powder, low temperature glasspowder, ethyl cellulose, terpineol, and dibutyl maleate. A mass ratio ofconductive powder:low temperature glass powder:ethylcellulose:terpineol:dibutyl maleate is 65 to 75:3:5 to 10:10 to 20:1 to3. The conductive powder is the graphene powder or the mixture of metalpowder and graphene powder. When the conductive powder is the mixture ofmetal powder and graphene powder, the graphene powder accounts for 2% to5% by mass of the conductive paste, wherein the shape of metal particlesin the conductive paste is polyhedral.

Step (2): To bake the glass substrate 1-1, covered with the conductivepaste, at a temperature between 120 and 150° C. for 100 to 200 seconds.

Step (3): To place the glass substrate 1-1 at a temperature between 550and 600° C. for 300 to 360 seconds, then to place at a temperaturebetween 710 and 730° C. for 120 to 220 seconds, and finally to cool toroom temperature to form the conductive circuit 1-2 distributed on thesurface of the glass substrate 1-1 and fused with the surface of theglass substrate 1-1, wherein the conductive circuit 1-2 is to form apart of the glass substrate 1-1.

Step (4): To coat the conductive circuit 1-2 with theprinted-circuit-board (PCB) organic solder-resistant layer 1-4 by ascreen printing technique, wherein the surface of the conductive circuit1-2, except the region reserved for the solder pad 1-3 used for weldingthe component, is totally covered with the printed-circuit-board (PCB)organic solder-resistant layer 1-4. The printed-circuit-board (PCB)organic solder-resistant layer 1-4 is colorless. This coated process ofthe present invention is named for the second coated process.

In step (3), the glass substrate 1-1 can be tempered through a rapidcooling process. Thus, the glass substrate 1-1 of highly conductivetransparent glass-based circuit board 1 is a glass-tempered substrate.

The conductive past has a special ratio of the mixture. In the bakedprocess of the step (2) and the fused process of the step (3), the glasssubstrate 1-1 begins to soften at a temperature of 500° C., and surfacemolecules of the glass substrate 1-1 begin to be activated at atemperature of 550° C. The low-temperature glass powders are melted tobring the conductive powders to fused with activated surface moleculesof the glass substrate 1-1; meanwhile, the terpineol and the dibutylmaleate in the conductive paste are volatilized at a high temperature.In this stage, surface molecules of the glass substrate 1-1 are notactivated at a temperature of less than 550° C., and the glass substrate1-1 is easily broken at a temperature of more than 600° C. After fusedfor 5 to 6 minutes, the conductive powders begin to be activated at atemperature around 720° C. to fuse with more activated surface moleculesof the glass substrate 1-1 for 2 to 4 minutes. In this stage, thetemperature should not be less than 710° C. or more than 730° C. toprevent excessive deformation of the glass substrate 1-1. At this time,the molecules of the conductive powder have been fully fused with thesurface of the glass substrate 1-1, and the fusion is a molecular level.The bonding force of the highly conductive transparent glass-basedcircuit board 1 is stronger than the bonding force of the glass-basedcircuit board of the traditional process using the adhesive. The surfaceof the glass substrate 1-1 and the surface of the conductive circuit 1-2are at the same level to make the surface of the highly conductivetransparent glass-based circuit board 1 smooth. The highly conductivetransparent glass-based circuit board 1 is suitable for a variety ofapplications.

Metal particles in the conductive paste can be grinded into a shape ofsphere, cube or irregular polyhedron, wherein the metal particles,grinded into the shape of cubes, can be arranged neatly for improvingelectrical conductivity. The graphene powder accounts for 2% to 5% bymass of the conductive paste. Although the content of the graphene inthe conductive paste is very little, the arrangement of molecules of thegraphene are extremely dense, molecules of the graphene are light toenable to float on the surface of metal molecules, wear resistance ofthe graphene is higher than wear resistance of metal, and the graphenehas high conductivity. Thus, the conductive circuit 1-2 has still highconductivity. The graphene is almost transparent so the highlyconductive transparent glass-based circuit board 1 has high lighttransmittance.

The second coated process is used for protecting the conductive circuit1-2 and preventing oxidation of the surface of the conductive circuit1-2. The traditional process is a coated process or paste process (e.g.sintering and coating film). The second coated process is that twomaterials are bond by intermolecular interpenetration so the twomaterials can be firmly bonded and cannot be easily peeled off After thesecond coated process, the surface of the highly conductive transparentglass-based circuit board 1 is still smooth, and the solder pad 1-3 canbe used for welding the component (e.g. an electronic component).

The highly conductive transparent glass-based circuit board 1 has alight transmittance of more than 90% and has the characteristic ofsuperconductivity, wherein the electrical impedance of the conductivecircuit 1-2 of the highly conductive transparent glass-based circuitboard 1 is lower than 5×10⁻⁸ Ω. The conductive circuit 1-2 is bonding tothe glass substrate 1-1 without any bonding medium so the conductivecircuit 1-2 has the characteristic of good thermal conductivity in highpower applications. The conductive circuit 1-2 is tightly fused withsurface molecules of the glass substrate 1-1, wherein asurface-mounted-device (SMD) can be bonded on the conductive circuit 1-2and the surface-mounted-device (SMD) is not easily peeled off.

The highly conductive transparent glass-based circuit board 1 iscombined with the adhesive film 2 and the other glass plate of the twoglass plates 3 to form the highly conductive transparent laminated glassarticle. The highly conductive transparent laminated glass article notonly has the characteristics of heat insulation and sound insulation inthe laminated glass article of the prior art, but also has thecharacteristics of high conductivity and high light transmittance. Thehighly conductive transparent laminated glass article is suitable forfabrication, manufacture, and use of industrial and smart-home devices.

1. A highly conductive transparent laminated glass article, comprising:two glass plates, at least one of the two glass plates being a highlyconductive transparent glass-based circuit board with a glass substrate;and an adhesive film, having a material of Poly(Vinyl Butyral) (PVB)resin and located between the two glass plates, wherein a surface of theglass substrate is not contact with the adhesive film, and a conductivepaste, printed on the surface of the glass substrate, is baked, heated,and cooled to form a conductive circuit fused with the surface of theglass substrate; wherein the conductive circuit is made essentially of agraphene layer or a conductive layer having a graphene upper portion anda metal lower portion fused with the glass substrate, and a surface ofthe graphene upper portion is fused with a surface of the metal lowerportion; wherein the glass substrate is a glass-tempered substrate, anda surface of the conductive circuit, except a region reserved for asolder pad used for welding a component, is covered with aprinted-circuit-board (PCB) organic solder-resistant layer; wherein theconductive paste includes conductive powder, low temperature glasspowder, ethyl cellulose, terpineol, and dibutyl maleate at a mass ratioof 65 to 75:3:5 to 10:10 to 20:1 to 3, and the conductive powder isgraphene powder or a mixture of metal powder and graphene powder;wherein, when the conductive powder is the mixture of metal powder andgraphene powder, the graphene powder accounts for 2% to 5% by mass ofthe conductive paste; and wherein a surface of the glass-temperedsubstrate faces air, and the conductive paste, printed on the surface ofthe glass-tempered substrate, is baked at a temperature between 120 and150° C. for 100 to 200 seconds, placed at a temperature between 550 and600° C. for 300 to 360 seconds, then placed at a temperature between 710and 730° C. for 120 to 220 seconds, and finally cooled to form theconductive circuit fused with the surface of the glass-temperedsubstrate.
 2. The highly conductive transparent laminated glass articleof claim 1, wherein the surface of the glass substrate and an uppersurface of the conductive circuit are at the same level.
 3. The highlyconductive transparent laminated glass article of claim 1, wherein thethickness of each of the two glass plates is 5 mm to 8 mm.
 4. The highlyconductive transparent laminated glass article of claim 1, wherein thethickness of the adhesive film is 1 mm to 2 mm.
 15. The highlyconductive transparent laminated glass article of claim 3, wherein thethickness of each of the two glass plates is 6 mm, and the thickness ofthe adhesive film is 1.14 mm.